1. Technical Field
The present invention is related to a touch-sensitive display apparatus, in particular to the display apparatus having a transparent substrate on which a plurality of electrode lines are formed to cover the subpixels of every pixel.
2. Description of Related Art
The general touch-sensitive module applied to a touch-sensitive display is such as a circuit substrate used to sense the touch event on the display. This circuit substrate is usually a transparent substrate. Upon the transparent substrate, a plurality of electrodes made of conductive materials are formed as the circuit for sensing the touch event in the touch-sensitive display. One of the types of the electrodes is such as the lines made of conductive material, for example the metal. The electrode line has a certain width. The two lines define an intersection that causes the X-direction and Y-direction signals when any touch event thereon is detected. The signals will drive an application program to act reflecting the operation made by the touching behavior.
The relevant technology may be referred to the schematic diagram of the conventional touch-sensitive display apparatus in FIG. 1.
The touch-sensitive display apparatus shown in the diagram essentially includes a touch-sensitive substrate 103 and electrode lines formed upon the top and bottom surfaces thereof. The shown lines are such as the row electrode lines 101 and the column electrode lines 102. A panel 10 is therefore formed as fabricating the substrate 103 and the electrodes. This panel 10 is then combined with a top lid 105 by an adhesive 104, and with the display panel 107 using an adhesive 106.
The materials to make the touch-sensitive substrate 103 are such as glass, plastics, or a blend of glass and plastics. The row electrode line 101 and column electrode line 102 are respectively formed along x-direction and y-direction. The capacitance effect is induced to form an electric field while a user's fingers touch the touch-sensitive panel. The interlaced electrode lines 101, 102 allow precisely determining the position to be touched.
The types of the conventional electrodes may be referred to FIG. 2A which shows a capacitance-type touch-sensitive panel. The diagram exemplarily shows an electrode layout of the touch-sensitive panel. The layout has row electrode lines 203 and column electrode lines 204. Each cross point made by the interlaced electrode lines 203, 204 is preferably positioned onto each pixel 20 on the display. The cross points allow determining the pixels associated with the positions to be touched. Parasitic capacitor 201 exists onto the pixel 20 where the row electrode line 203 and the column electrode line 204 are intersected.
The parasitic capacitor 201 is induced to be a signal capacitor 202 when current flows across the parasitic capacitor 201 and changes the electric field between the electrode lines 203, 204. On the other words, the touching event changes the electric field across the capacitor of the panel; that means the finger, palm or other parts of the human body inducing the change of the signal capacitor 202. The signal capacitor 202 associated with the row electrode line 203 and the column electrode line 204 is used to sense the position to be touched.
Reference is made to FIG. 2B schematically showing a relationship of the electrode lines and the pixels in the conventional technology. A series of pixels are presented on a display panel orderly. The each pixel is composed of subpixels with different colors. In an example, the subpixels are such as red subpixel (R), green subpixel (G), and blue subpixel (B). The row electrode lines 203′ and column electrode lines 204′ are interlaced above the pixels. It is noted that the each cross point of row electrode lines 203′ and the column electrode line 204′ is approximately covered over the center of the each pixel.
FIG. 2C again shows the diagram of the relationship of one pixel and the crossed electrode lines. One enlarged pixel 20 including a red subpixel, green subpixel and blue subpixel is shown in the diagram. This example shows a cross point of the row electrode line 203″ and the column electrode line 204″ on the touch-sensitive panel is positioned onto center of the green subpixel.
According to the descriptions related to the FIG. 2B or FIG. 2C, in the conventional technology the electrode lines of the touch-sensitive panel are usually designed to be formed along longitudinal and horizontal directions. The cross points therein can be located at the center of each pixel as far as possible. In FIG. 2C, the cross point locates at the central subpixel of the pixel. Accordingly, since the electrode line has a certain width, the subpixel(s) may be partly shielded. The effect of shield may result in obscuring the brightness of the subpixel(s). Furthermore, the colors illuminated may not be uniform since the every subpixel meets different shielding conditions. At last, the displayed frame may have color shift caused by the uneven colors illuminated from the subpixels.
For example, the conventional touch-sensitive panel includes longitudinal and horizontal sensing electrodes thereon, and the electrodes may merely cover one of the subpixels in each pixel. Thus the colors of the each pixel may not be uniform and make bad display quality.
A tolerance of fabricating the display may exist and result in poor accuracy as combining the touch-sensitive panel with the display panel. In addition to the above-described color shift made by the uneven shielding effect for each pixel, the tolerance may cause the uneven brightness because of the inconsistent matching between the sensing electrodes and the pixels. The mentioned at least two shortcomings may together generate much greater color shift.